Modulating cerebello-thalamocortical pathways by neuronavigated cerebellar repetitive transcranial stimulation (rTMS).
OBJECTIVE
Increasing evidence suggests that dysfunctions of the cortico-cerebello-thalamocortical circuit are involved in the pathophysiology of neuropsychiatric disorders. This study explores the effects of cerebellar repetitive transcranial magnetic stimulation (rTMS) on cerebello-thalamocortical pathways.


METHODS
Ten healthy volunteers received MRI-guided rTMS in four separate sessions (120% motor threshold, 1000 stimuli) over either the medial or the right lateral cerebellum using frequencies of 1 and 10 Hz. Motor cortex excitability was assessed before and after the intervention by paired-pulse transcranial magnetic stimulation.


RESULTS
Depending on stimulation frequency, cerebellar rTMS differentially modified intracortical inhibition. Low frequency rTMS increased short intracortical inhibition (SICI), whereas high frequency rTMS had no significant effect on SICI.


CONCLUSIONS
These results suggest that rTMS over the cerebellum can modulate cerebello-thalamocortical pathways in a frequency-specific manner.
Langguth
B
B
Department of Psychiatry, Psychosomatics and Psychotherapy, University of Regensburg, Universitaetsstrasse, 84, 93053 Regensburg, Germany. Berthold.Langguth@medbo.de
Eichhammer
P
P
Zowe
M
M
Landgrebe
M
M
Binder
H
H
Sand
P
P
Hajak
G
G
D000328:Adult; D002531:Cerebellum / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology*; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology; D013788:Thalamus / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult